Question

Sex determination in animals such as humans and insects is done using the XX-XO and XX-XY mechanisms. In some organisms ZZ-ZW mechanism of sex determination is seen.
Based on the given statement, answer the question given below.

Individuals who have homomorphic sex - chromosomes produce
[1 mark]

• A. two types of gametes
• B. no gametes
• C. one type of gamete
• D. only one gamete in a complete life span

Answer 1

The correct option is C one type of gamete

Homomorphic word comes from the ancient Greek word ‘homos’ meaning “same” and ‘morphe’ means ‘form’. Hence, individuals having homomorphic sex - chromosomes, i.e, sex chromosomes that are identical to each other, produce one type of gamete. For example, human females (having XX sex chromosomes) produce gametes with 22+X chromosomes only.

Individuals having heteromorphic sex - chromosomes can produce two types of gametes. For example, human males (having XY sex chromosomes) can produce gametes having 22+X or 22+Y chromosomes.